All categories

3 years ago

What is the simplest form of the expression 2x(x − 6) − 7x2 − (13x − 3)?

Mathematics

2 answers:

inna [77]3 years ago

7 0

Answer:

The answer for me was B, but it may be different if the test mixes up the answers... the numerical answer is -5x^2 - 25x +3.

Step-by-step explanation:

I just took the final and got a 100%

lina2011 [118]3 years ago

6 0

Answer:

D. -5x² - 25x - 3

Step-by-step explanation:

Simply distribute where needed, evaluate the distribution, then combine like-terms to arrive at your answer.

You might be interested in

Lines ℓ and m are intersected by transversal t. ℓ ∥ m. Lines l and m are horizontal with l above m and intersected by transveral

artcher [175]

Answer:

<5 = 105 degrees

Step-by-step explanation:

From the description given, since line l is parallel to m then <4 is alternate to <5 and two alternate angles are equal, if thst is the case

<4 = <5 (alternate angle)

Since <4 = 105 degrees, hence m<5 = 105 degrees

7 0

3 years ago

A certain article indicates that in a sample of 1,000 dog owners, 610 said that they take more pictures of their dog than of the

lbvjy [14]

Answer:

(a) The 90% confidence interval is: (0.60, 0.63) Correct interpretation is (3).

(b) The 95% confidence interval is: (0.42, 0.46) Correct interpretation is (1).

(c) First, the confidence level in part(b) is more than the confidence level in part(a) is, so the critical value of part(b) is more than the critical value of part(a), Second the margin of error in part(b) is more than than in part(a).

Step-by-step explanation:

(a)

Let X = number of dog owners who take more pictures of their dog than of their significant others or friends.

Given:

X = 610

n = 1000

Confidence level = 90%

The (1 - α)% confidence interval for population proportion is:

$CI=\hat p\pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

The sample proportion is:

$\hat p=\frac{X}{n}=\frac{610}{1000}=0.61$

The critical value of z for a 90% confidence level is:

$z_{\alpha/2}=z_{0.10/2}=z_[0.05}=1.645$

Construct a 90% confidence interval for the population proportion of dog owners who take more pictures of their dog than their significant others or friends as follows:

$CI=\hat p\pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}\\=0.61\pm 1.645\sqrt{\frac{0.61(1-0.61}{1000}}\\=0.61\pm 0.015\\=(0.595, 0.625)\\\approx(0.60, 0.63)$

Thus, the 90% confidence interval for the population proportion of dog owners who take more pictures of their dog than their significant others or friends is (0.60, 0.63).

Interpretation:

There is a 90% chance that the true proportion of dog owners who take more pictures of their dog than of their significant others or friends falls within the interval (0.60, 0.63).

Correct option is (3).

(b)

Let X = number of dog owners who are more likely to complain to their dog than to a friend.

Given:

X = 440

n = 1000

Confidence level = 95%

The (1 - α)% confidence interval for population proportion is:

$CI=\hat p\pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

The sample proportion is:

$\hat p=\frac{X}{n}=\frac{440}{1000}=0.44$

The critical value of z for a 95% confidence level is:

$z_{\alpha/2}=z_{0.05/2}=z_{0.025}=1.96$

Construct a 95% confidence interval for the population proportion of dog owners who are more likely to complain to their dog than to a friend as follows:

$CI=\hat p\pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}\\=0.44\pm 1.96\sqrt{\frac{0.44(1-0.44}{1000}}\\=0.44\pm 0.016\\=(0.424, 0.456)\\\approx(0.42, 0.46)$

Thus, the 95% confidence interval for the population proportion of dog owners who are more likely to complain to their dog than to a friend is (0.42, 0.46).

Interpretation:

There is a 95% chance that the true proportion of dog owners who are more likely to complain to their dog than to a friend falls within the interval (0.42, 0.46).

Correct option is (1).

(c)

The confidence interval in part (b) is wider than the confidence interval in part (a).

The width of the interval is affected by:

The confidence level
Sample size
Standard deviation.

The confidence level in part (b) is more than that in part (a).

Because of this the critical value of z in part (b) is more than that in part (a).

Also the margin of error in part (b) is 0.016 which is more than the margin of error in part (a), 0.015.

First, the confidence level in part(b) is more than the confidence level in part(a) is, so the critical value of part(b) is more than the critical value of part(a), Second the margin of error in part(b) is more than than in part(a).

4 0

3 years ago

You made two deposits to your bank accounts this month. One deposit was $17.92, and the second deposit was $15.33. Your balance

WITCHER [35]

$72.31 is the total amount AFTER ADDING TWO DEPOSITS

So, if we want to know the amount before deposits, we just need to take the total of previous two deposits

The expressions that show your balance would be

$72.31 – $17.92 – $15.33; $39.06

6 0

3 years ago

If f(x)=2x-4, what would be the answer if f(3)-1??

Vinil7 [7]

Answer:

Step-by-step explanation:

We have the function

$f(x) = 2x - 4$